PDBsum entry 2jcp

Sugar binding protein

PDB id: 2jcp

Contents

Protein chain

150 a.a. *

Waters ×178

* Residue conservation analysis

PDB id:

2jcp

Name:

Sugar binding protein

Title:

The hyaluronan binding domain of murine cd44

Structure:

Cd44 antigen. Chain: a. Fragment: hyaluronan binding domain, residues 23-174. Synonym: phagocytic glycoprotein 1, pgp-1, hutch-i, extracellular matrix receptor iii, gp90 lymphocyte homing/adhesion receptor, hermes antigen, hyaluronate receptor, lymphocyte antigen ly-24, cd44. Engineered: yes. Other_details: encoded residues 25-174, equivalent to residues 1-151 of the mature protein, with additional residues m, n added at the n-

Source:

Mus musculus. Mouse. Organism_taxid: 10090. Expressed in: escherichia coli. Expression_system_taxid: 511693. Expression_system_variant: de3 plyss.

Resolution:

1.30Å R-factor: 0.158 R-free: 0.191

Authors:

S.Banerji,A.J.Wright,M.E.M.Noble,D.J.Mahoney,I.D.Campbell,A.J.Day, D.G.Jackson

Key ref:

S.Banerji et al. (2007). Structures of the Cd44-hyaluronan complex provide insight into a fundamental carbohydrate-protein interaction. Nat Struct Biol, 14, 234-239. PubMed id: 17293874 DOI: 10.1038/nsmb1201

Date:

03-Jan-07 Release date: 30-Jan-07

Protein chain

P15379  (CD44_MOUSE) -  CD44 antigen from Mus musculus

Seq: 778 a.a.

Struc: 150 a.a.

DOI no: 10.1038/nsmb1201

Nat Struct Biol 14:234-239 (2007)

PubMed id: 17293874

Structures of the Cd44-hyaluronan complex provide insight into a fundamental carbohydrate-protein interaction.

S.Banerji, A.J.Wright, M.Noble, D.J.Mahoney, I.D.Campbell, A.J.Day, D.G.Jackson.

ABSTRACT

Regulation of transient interactions between cells and the ubiquitous matrix glycosaminoglycan hyaluronan is crucial to such fundamental processes as embryonic development and leukocyte homing. Cd44, the primary cell surface receptor for hyaluronan, binds ligand via a lectin-like fold termed the Link module, but only after appropriate functional activation. The molecular details of the Cd44-hyaluronan interaction and hence the structural basis for this activation are unknown. Here we present the first crystal structure of Cd44 complexed with hyaluronan. This reveals that the interaction with hyaluronan is dominated by shape and hydrogen-bonding complementarity and identifies two conformational forms of the receptor that differ in orientation of a crucial hyaluronan-binding residue (Arg45, equivalent to Arg41 in human CD44). Measurements by NMR indicate that the conformational transition can be induced by hyaluronan binding, providing further insight into possible mechanisms for regulation of Cd44.

Selected figure(s)

Figure 1.
(a) Final refined 1.25-Å-resolution 2F[o] – F[c] electron density for the binding site in the type A crystal complex, calculated using SIGMAA^31 weighted map coefficients generated by REFMAC^32 is contoured at 0.25 e^- Å^-3 (equivalent to the s.d. of the final map). Refined structure is shown as sticks colored by atom type (green, Cd44 carbons; cyan, HA carbons; blue, nitrogen; red, oxygen; yellow, sulfur). Individual sugar rings in the bound HA[8] oligosaccharide are numbered from the nonreducing end. (b) A ribbon diagram of mouse Cd44 (type B complex), with secondary structure identified using the DSSP algorithm^33. Pink, -helices; white, loops; green and gold, -sheets I and II, respectively; cyan, bound HA. (c) Surface representation of the HA-binding site in the type B crystal complex. The shallow HA-binding groove is shown as molecular surface. Gold, supplementary lobe formed from N- and C-terminal Link extensions; cyan, HA. Selected residues marking the boundaries of the groove are labeled. The type A crystal form shows similar features but lacks the lower platform for the HA interaction provided by reorientation of Arg45.

Figure 2.
(a,b) The core of the HA-binding site (a) and the full binding groove in the type B crystal complex (b) are shown as sticks, colored as in Figure 1a. Dotted lines denote hydrogen bonds (identified as contacts between polar atoms closer than 3.4 Å). Numbers indicate individual sugar rings, as in Figure 1a.

The above figures are reprinted by permission from Macmillan Publishers Ltd: Nat Struct Biol (2007, 14, 234-239) copyright 2007.

Figures were selected by an automated process.